1. Field of the Invention
The present invention is directed to improvements in heated banquet carts that overcome many of the problems of conventional carts. Specifically, the present invention is directed to a cart that is more maneuverable, provides better and more efficient interior heat circulation, and provides improved operating information to the user.
Generally speaking, the present invention will be referred to as a “cart,” which is maneuverable and which incorporates an enclosed “cabinet” for storing heated items such as food.
2. Description of the Related Art
Conventional banquet carts are known in the art. Such banquet carts are commonly used for storing and transporting prepared foods. An example of such a cart is shown in U.S. Pat. No. 4,108,518 (Angst). In addition, conventional carts are available from such companies as InterMetro Industries Corporation (www.intermetro.com), which is related to the assignee of the present invention, Carter-Hoffman (www.carter-hoffman.com), and Food Warming Equipment, Inc. (www.fweco.com).
Typically, such banquet carts have a generally rectangular horizontal cross-sectional shape or footprint. The cabinet incorporated with the cart has one or more doors that open to reveal shelves or the like for supporting plates, food service trays and similar food service items. This structure allows a user to store inside of the cabinet prepared meals that are ready for service. The walls and doors of the cabinet are typically thermally insulated so that the cabinet will retain heat, which serves to keep the prepared foods warm before they are served.
To aid in keeping prepared foods warm, some conventional banquet cabinets also include electric heaters that can be plugged into an electrical outlet in order to maintain an elevated temperature inside the cabinet. It is also known to use chaffing fuel canisters (such as STERNO® fuel canisters) to provide heat to the interior of the cabinet when, for example, a source of electrical power is not readily available. Typically, the chaffing fuel canisters are ignited and positioned at the bottom of the cabinet in order to provide heated air to plates or service trays stored on the shelving above the canisters. High-end carts often include a combination of an electric heating unit and a supplemental heating unit designed for holding and distributing heat provided by chaffing fuel, to provide the user with multiple heating options.
In addition to merely keeping food warm, conventional banquet carts also allow for transporting of the stored food. A typical cart is configured such that its base is supported on wheels or casters, allowing the cart to be moved from food preparation areas, to “staging” areas where food is held before ultimate service. From the staging areas, the plates or service trays can be removed from the heated cabinet and delivered to dining guests in a banquet hall, for instance.
While these conventional banquet carts are adequate for their intended purpose, they are characterized by certain drawbacks yet unsolved in the art. In particular, when chaffing fuel canisters are used, it is difficult to circulate the heated air that they provide evenly throughout the cart. Also, because many carts may be used when serving a large group of people, it can become difficult to keep track of which food items are stored in the various carts, and the length of time during which those food items have been stored. In addition, when multiple carts are aligned side-by-side, the maneuverability of one cart positioned between other carts can be difficult with the conventional arrangement of wheels or casters at the base of the carts. These problems will be discussed in more detail below.
Problems Related to the Use of Chaffing Fuels
As noted, when electric heating units cannot be used conveniently, users often just place chaffing fuel canisters in the bottom of the banquet carts. In such situations, the plates or trays positioned on shelves directly above the burning chaffing fuel often become too hot too quickly. Also, in the absence of a fan or suitable heat transfer mechanism for circulating the heated air, the plates on shelves at the top of the cabinet often cool too rapidly.
To compensate for this disparity in heat distribution, some manufacturers offer specialized systems for handling chaffing fuels. The specialized systems may include heat shields which protect items stored on lower level shelves from overheating, and chimneys for distributing heat provided by the chaffing fuel more evenly throughout the cabinet.
Conventionally, such chimneys are provided along the back or side walls of the cabinet. Also, the chimneys usually have rectangular cross-sectional shapes. While this may provide for adequate circulation of heated air in some instances, the configuration and placement of such chimneys often leads to either a reduction in the holding capacity of the cart, or an increase in the size of the footprint of the cart, to compensate for the space occupied by the chimneys. Accordingly, there is a need for a cabinet that is easy to manufacture, and in which chaffing fuels can be effectively used without the loss of valuable interior storage space or the unnecessary expansion of the exterior size of the cart.
Problems Related to Maneuverability
Logistics often require the use, movement, and positioning of multiple carts.
Commonly, banquet carts are moved both along straight lines and through curves to their final destinations. In these conditions, the carts are easily moved where two casters on a trailing or rear end (in the direction of cart movement) are free to swivel and two wheels on a second or leading end are fixedly secured so as not to swivel and to be aligned so that their planes of rotation are substantially parallel with the direction of movement, when the cart is pushed or pulled in a straight line. This common configuration, much like the reverse of the configuration of a common shopping cart, allows for maneuvering the cabinet along straight lines and through turns. However, banquet carts are sometimes positioned end-to-end along a wall or the like in the staging area. The above-discussed arrangement of casters and wheels makes it difficult to move an individual banquet cart sideways in to or out of a row of carts. In such cases, it is possible to have all of the wheels comprise swivel casters, to provide easy movement in a sideways direction (that is, perpendicular to the end-to-end row in which the cart is positioned). However, with four swivel casters, maneuvering the cart in a straight line over long distances and through curves becomes difficult for a user.
Accordingly, there is a need in the art to provide a more maneuverable banquet cart to overcome the problems of conventional carts.
While not relating to heated banquet carts, each of U.S. Pat. Nos. 4,875,696 (Welch, et al.) and 4,790,610 (Welch, et al.) disclose mechanisms for locking casters supporting a cart in particular orientations. However, as will be explained further below, those mechanisms are not entirely suitable in the present application.
Problems Related to Information Management
It is also useful to a user to be able to ascertain quickly information such as the contents of the banquet cart, how long food has been stored in the banquet cart, when chaffing fuel canisters will likely need to be replaced, and the temperature of the inside of the banquet cart, among other data. These needs are exacerbated by the fact that service of food involving banquet carts can be fast paced, with the meals needing to be served without having become too cold or having become over cooked or dried out from prolonged heat exposure.
Conventional banquet carts do not provide much of this desirable information to the user. While many conventional carts include temperature gages, such a feature alone is not always helpful to a user. For instance, although a user can readily ascertain the temperature of the inside of the banquet cart by referring to a gage, he or she cannot determine how long the food has been stored at that temperature.
Also, while some conventional banquet carts offer windows for viewing the contents, they do not provide a reliable way to determine the state of the whole of the cart contents. Specifically, plates of food are often stacked many deep in the cart, such that a window alone will not allow a user to determine what is in the back of the cart. In addition, the plates may be covered during storage in the cart, rendering windows useless. Still further, windows add to the manufacturing cost and can lead to increased heat loss.
Thus, there is a need to provide users with readily accessible information that can aid in the monitoring and managing of banquet carts and the food stored in them.